Inconsistent UI, bad ergonomics, laggy display. It stutters when you move the map around, buttons look different in different parts of the system, and the steering wheel has 20+ buttons.
Things like volume or cruise control speed adjust are touch/swipe motions over flat plastic on the steering wheel. No tactile feedback, so you never end up at the speed that you wanted without 3 attempts.
And their driver assist function gets at least half of the speed signs wrong. Not just a few like most cars but half. Even in inconsistent ways where the display will show a "higway" icon so it has seen the sign, and then remain at 50km/h for no reason instead of showing 130.
The model I drove didn't have lane keeping or auto steer, but still beeped at me once in a while to keep my hands on the wheel even though I had them there. Probably I didn't show enough steering input, but why? Without lane keeping what's the point of that warning?
This car to me felt like the people who design these things never drive one.
Mercedes was the aspirational brand for professionals: 50+ years old doctors and lawyers looking for a solid and reliable premium car for grown ups.
Then the disaster of a CEO that looked at it and said: we want to bring the average age of the Mercedes Benz buyer 10 years down to early 40s.
Mercedes became younger and sportier, needlessly cornering itself in the same niche of Audi and BMW at home alone.
Car interiors became tacky as entering a sauna or something. Reliability, what it was known for went down.
It's like Mercedes Benz completely does not understand its own brand.
And the SL Mercedes is s clear sign of it. 200k of a car that screams "this guy is clueless why didn't he got a 911 instead". And of course Porsche sells tons more in that gran turismo price range, you see tons of them, I swear I saw like a handful of those SLs.